Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
hoc thieu » toc thieu, hoc hien
thong den » thong dien, thong dan, tuong den
ho chieu » theo chieu, doi chieu, mot chieu
trinh he » trinh han, trinh hoa, trinh thi
den toan » dien toan, dan toan, den tran
toan ban » van ban

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho chieu) or (hoc thieu)) xanh - canh trinh he thong thong den toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) xanh - canh trinh he thong thong den toan ban*.